Search results for "Mating"
showing 10 items of 387 documents
Female-released sex pheromones mediating courtship behavior in Lysiphlebus testaceipes males
2013
Ethological aspects and chemical communication at close-range between the sexes of Lysiphlebus testaceipes Cresson (Hymenoptera: Braconidae) have been investigated through behavioral bioassays and chemical analysis. The attractiveness toward males of whole-body extracts of females and males in hexane and acetone was evaluated, adopting male fanning behavior as a key behavioral component. Also, the activity of polar and nonpolar fraction of female-body extract in hexane obtained using solid-phase extraction technique was investigated. In order to identify cuticular compounds, male and female whole-body extracts with hexane and acetone were analyzed by gas chromatography-mass spectrometry. Th…
A sex pheromone triggers courtship behaviour in the egg parasitoid Trissolcus brochymenae
2010
Quantification of sexual dimorphism in Asellus aquaticus (Crustacea: Isopoda) using outline approaches
2002
A marked sexual dimorphism is often observed in arthropods species in which males perform precopulatory mate guarding. It is generally thought to reflect the influence of sexual selection. Until now, sexual dimorphisms associated with mate guarding have mainly been qualitatively described. However, assessing the effects of sexual selection on sexual dimorphims requires a preliminary quantitative assessment of differences in morphology between sexes. Using Fourier analyses, we tested if morphological dimorphisms could be quantitatively assessed in the isopod Asellus aquaticus. In addition, we checked whether sexual dimorphism in shape was exclusively related to mate guarding through consider…
Sperm competition and small size advantage for males of the golden orb-web spider Nephila edulis
2000
Sexual selection, through female choice and/or male‐male competition, has influenced the nature and direction of sexual size dimorphism in numerous species. However, few studies have examined the influence of sperm competition on size dimorphism. The orb-web spider Nephila edulis has a polygamous mating system and extreme size dimorphism. Additionally, the frequency distribution of male body size is extremely skewed with most males being small and few large. The duration of copulation, male size and sexual cannibalism have been identified as the significant factors determining patterns of sperm precedence in spiders. In double mating trials, females were assigned to three treatments: either…
Behavioral roles of the sexually dimorphic structures in the male harvestman, Phalangium opilio (Opiliones, Phalangiidae)
2006
Abstract: In various animal species, male sexual dimorphic characters may be used during intrasexual contests as ornaments to attract females, or to hold them before, during, or after copulation. In the well-known harvestman, Phalangium opilio L., 1758, the behavioral functions of these male sexually dimorphic structures have never been studied in detail. Therefore, in addition to a morphometric study, 21 male contests and 43 sexual interactions were analyzed. Our observations revealed that during contests, the male cheliceral horns form a surface by which the contestants use to push each other face-to-face while rapidly tapping their long pedipalps against the pedipalps of the opponent, oc…
From Dating to Mating and Relating: Predictors of Initial and Long–Term Outcomes of Speed–Dating in a Community Sample
2011
We studied initial and long–term outcomes of speed–dating over a period of 1 year in a community sample involving 382 participants aged 18–54 years. They were followed from their initial choices of dating partners up to later mating (sexual intercourse) and relating (romantic relationship). Using Social Relations Model analyses, we examined evolutionarily informed hypotheses on both individual and dyadic effects of participants’ physical characteristics, personality, education and income on their dating, mating and relating. Both men and women based their choices mainly on the dating partners’ physical attractiveness, and women additionally on men's sociosexuality, openness to experience, …
Predictors of enhancing human physical attractiveness: Data from 93 countries
2022
People across the world and throughout history have gone to great lengths to enhance their physical appearance. Evolutionary psychologists and ethologists have largely attempted to explain this phenomenon via mating preferences and strategies. Here, we test one of the most popular evolutionary hypotheses for beauty-enhancing behaviors, drawn from mating market and parasite stress perspectives, in a large cross-cultural sample. We also test hypotheses drawn from other influential and non-mutually exclusive theoretical frameworks, from biosocial role theory to a cultural media perspective. Survey data from 93,158 human participants across 93 countries provide evidence that behaviors such as a…
Speciation in monogonont rotifers
1997
Monogonont rotifers are cyclical parthenogens livingin limnic habitats with considerable seasonalvariation and often with island-like features. Theoccurrence of bisexual reproduction in these organismsmakes it feasible to define ’fields for generecombination‘, i.e. biological species. In thispaper, we analyze the structure of the diversity inmonogonont rotifers using several data sets: taxonomicand intraspecific diversity as reported inidentification keys, morphological variation reportedin ecological studies, and allozyme and matingbehavior patterns. Our analysis suggests that siblingspecies may be frequent in rotifers. Monogonontrotifers seem to meet conditions for an activespeciation, wh…
Pre- and post-mating reproductive barriers drive divergence of five sympatric species of Naryciinae moths (Lepidoptera: Psychidae)
2014
The biological species concept suggests that species can be separated on the basis of reproductive isolation. However, because natural interbreeding capabilities are often unknown, differences in morphology are generally used to separate species. Alternatively, genetic dissimilarity is used to separate morphologically similar species. Many genetic markers, including the maternally inherited mitochondrial cytochrome oxidase I sequence, cannot show interbreeding and therefore species status of groups may remain unresolved. In species of the genera Dahlica and Siederia (Lepidoptera: Psychidae: Naryciinae) the lack of morphological distinction and unknown interbreeding has led to unclear and un…
Overwintering survival in relation to body mass in a field population of the wolf spider ( Hygrolycosa rubrofasciata )
1999
Body size is often considered to be an important trait affecting individual fitness. In arthropods, females commonly benefit from larger size directly through increased fecundity (Roff, 1992), and males through increased mating success (Andersson, 1994). It has also been suggested that larger individuals may in general have a better survival than smaller individuals (Calder, 1983; Peters, 1983). From this suggestion it may be predicted that during stressful environmental conditions larger individuals should do better than smaller individuals.